1. Field of the Invention
The present invention relates to a photoelectric conversion module with redundancy, and a manufacturing method thereof.
2. Description of the Related Art
In recent years, a photoelectric conversion device that generates power without carbon dioxide emissions has attracted attention as a countermeasure for global warming. A typical example is a solar battery using crystalline silicon that generates power with solar light from outside by being set on a roof or the like of a residential house, as well as a solar battery using amorphous silicon that has a high photoelectric conversion ability with respect to wavelength of visible light ray, such as light of a fluorescent lamp.
Amorphous silicon solar batteries are thin-film solar batteries, and have an advantage that they can be manufactured at a low cost. However, thin-film solar batteries are structurally weak against tiny defects, and electrical characteristics can be degraded due to structural defects such as pinholes and scratches.
The structural defects cause short-circuits and leak currents by their own effects or by affecting another process and reducing parallel resistance between electrodes of a solar battery. Even if a leak current is very small, under low illuminance that generates little electrical current, electrical characteristic of the solar cell becomes extremely degraded.
As a means for solving such problems, Patent Document 1 discloses a method of preventing a short circuit between top and bottom electrodes by applying a photo-resist over a semiconductor layer that has a structural defect and prebaking it to fix the photo-resist on the structural defect, and then unfixing unnecessary photo-resist that is over the semiconductor layer by ultraviolet light irradiation and removing it by a development process.
Also, Patent Document 2 discloses a method of preventing a short-circuit between one electrode and another electrode through a structural defect, by performing connection of a semiconductor layer and one of the electrodes in a plurality of open portions of an insulating layer that is formed over the semiconductor layer.